Caller ID is a well-known feature whereby the directory number of a calling party is displayed on a recipient's phone coincident to ringing the called party phone for an incoming call. The recipient may screen the call by viewing the directory number before choosing to answer the call and in such manner, the recipient may avoid certain calls from unrecognized or undesired calling parties. Caller ID information may also be used to automatically block certain calls or to provide different call treatment (e.g., directing the call to a messaging system) without ringing the called party phone. Accordingly, Caller ID is presently an effective tool for screening or blocking calls.
However, various countermeasures have evolved for the purpose of circumventing or reducing the efficacy of Caller ID. One such countermeasure comprises “spoofing” technology that causes the Caller ID feature to display the wrong name and/or number so as to disguise the identity of the true caller. In such manner, for example, a telemarketer or other undesired caller may steal the identity of a different legitimate caller and trick the called party into answering the phone. The spoofing paradigm has emerged as the telecommunications industry begins to shift toward packet-based technologies such as Voice over IP (“VoIP”).
Spoofing for the purpose of masking a marketer's identity is illegal under the Telemarketing Sales Rule, enforced by the Federal Trade Commission (FTC). However, loopholes exist in that a business may cause a different number to be displayed for an incoming call so long as the different number is owned by the business. In such manner, for example, a call from a salesperson's personal line may appear as if it originated from the company's main number. Moreover, the laws do not currently prevent the use of spoofing technology by individual citizens and thus there is a great potential for abuse by crank callers, stalkers and the like. Thus, it seems that the use of spoofing technology will continue, and perhaps even increase, in the foreseeable future. For so long as spoofing technology continues to be used, it threatens to undermine the Caller ID feature since the recipient no longer can trust the authenticity of the Caller ID information. Consequently, a need exists to preserve the benefits of Caller ID despite the presence of spoofing technology.